Oct 6 math questions

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1

<p>Did you get 2 for that z= series of equations?</p>

<p>also I read that you guys got 900 for the 4 digit number problem... if I can remember properly the first digit was 1, and the rest could only be POSITIVE integers and the digits couldn't repeat. So how is it not:</p>

<p>9 (the second digit has 8 options... 2, 3, 4, 5, 6, 7, 8, or 9) x 8 (the next digit has 7 options as it can't repeat the preceding digit) x 6 (once again the digit can't repeat the preceding digit) = 336? How did you get 900?</p>

<p>Let me know,
Thanks!</p>

2

<p>the digits can repeat.</p>

3

<p>I seriously thought the question said digits could not repeat as well, but evidently we were both mistaken.</p>

4

<p>indeed you were! i am positive this time, because i couldnt get it at first (im a idiot, i thought 10 was a integer so i was multiplying by 11, not 10) and i was like *** so i reread it like 5 times to see if digits couldnt repeat. the only question i read carefully!</p>

5

<p>1x10x10x9 = 900</p>

<p>1 is the only number that's possible (2)
10 digits x 10 digits x 9 digits (9 since one cannot be used)</p>

6

<p>We understand the question and how to solve. The only problem is whether or not the digits could repeat. It's painfully (literally) obvious to us why we were wrong >_></p>

7

<p>so you're saying the question noted that the 1 couldn't repeat but the other digits could? i'm confused... because if that's the case then it would be 1 x 9 x 9 x 9.</p>

<p>Andrew</p>

8

<p>The question said that the first digit had to be 2, and the last one couldn't be 0.</p>

<p>so 10<em>10</em>9.</p>

9

<p>0 is a integer. that would make 10 integers a possible choice. 1<em>10</em>10 and the last one zero couldnt be it, so it would be 9</p>

10

<p>true..but i distinctly remember it saying "positive integers"... doesn't that mean 0 doesn't count?</p>

11

<p>no. that wouldn't make sense. 9^3*1? that wasn't a answer choice.</p>

12

<p>it was a grid-in I believe, but it didn't say anything about a positive integer but rather it said integer.</p>

13

<p>the 900? that was not a gridin, that was on teh system of equations section. I remmeber, because at first i skipped it.</p>

14

<p>I am 100% positive it stated that the digits could not repeat. Guaranteed. I calculated 336. (A) was the correct answer.</p>

15

<p>It would 1x8x7x6. What were the other choices? Was 432 one of them? I know 336, 900, and 1000-something were there.</p>

16

<p>llewis - you are not correct; the numbers could repeat. 900 is the correct answer.</p>

17

<p>It was 900.</p>

<p>I went over it many times and I'm sure the digits were allowed to repeat...</p>

18

<p>Digits could repeat, sorry.</p>

19

<p>yeah, the numbers could repeat. it was 900.</p>